package com.example.demo.rpc;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.URL;
import java.net.URLConnection;
import java.util.List;
import java.util.Map;


/**
 * java发送http的get和post请求
 *
 * @author yzd
 */
public class HttpRequest {

	private static final Logger logger = LoggerFactory.getLogger(HttpRequest.class);

	/**
	 * 向指定URL发送GET方式的请求
	 *
	 * @param url   发送请求的URL
	 * @param param 请求参数
	 * @return URL 代表远程资源的响应
	 */
	public static String sendGet(String url, String param) {
		String result = "";
		String urlName = url + "?" + param;
		try {
			URL realUrl = new URL(urlName);
			//打开和URL之间的连接
			URLConnection conn = realUrl.openConnection();
			//设置通用的请求属性
			conn.setRequestProperty("accept", "*/*");
			conn.setRequestProperty("connection", "Keep-Alive");
			conn.setRequestProperty("user-agent",
					"Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
			//建立实际的连接
			conn.connect();
			//获取所有的响应头字段
			Map<String,List<String>> map = conn.getHeaderFields();
			//遍历所有的响应头字段
			for (String key : map.keySet()) {
				logger.info(key + "-->" + map.get(key));
			}
			// 定义 BufferedReader输入流来读取URL的响应
			BufferedReader in = new BufferedReader(new InputStreamReader(conn.getInputStream()));
			String line;
			while ((line = in.readLine()) != null) {
				result += line;
			}
		} catch (Exception e) {
			logger.error("发送GET请求出现异常" + e);
			e.printStackTrace();
		}
		return result;


	}

	/**
	 * 向指定URL发送POST方式的请求
	 * @param url  发送请求的URL
	 * @param param 请求参数
	 * @return URL 代表远程资源的响应
	 */
	public static String sendPost(String url, String param){
		String result = "";
		try{
			URL realUrl = new URL(url);
			//打开和URL之间的连接
			URLConnection conn = realUrl.openConnection();
			//设置通用的请求属性
			conn.setRequestProperty("accept", "*/*");
			conn.setRequestProperty("connection", "Keep-Alive");
			conn.setRequestProperty("user-agent",
					"Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
			//发送POST请求必须设置如下两行
			conn.setDoOutput(true);
			conn.setDoInput(true);
			conn.setConnectTimeout(500000);
			conn.setReadTimeout(500000);
			//获取URLConnection对象对应的输出流
			PrintWriter out = new PrintWriter(conn.getOutputStream());
			//发送请求参数
			out.print(param);
			//flush输出流的缓冲
			out.flush();
			// 定义 BufferedReader输入流来读取URL的响应
			BufferedReader in = new BufferedReader(new InputStreamReader(conn.getInputStream(), "utf-8"));
			String line;
			if ((line = in.readLine()) != null) {
				result += line;
			}
			while ((line = in.readLine()) != null) {
				result += "\n" + line;
			}
		} catch (Exception e) {
			logger.error("发送POST请求出现异常" + e);
			e.printStackTrace();
		}
		return result;
	}

	//测试发送GET和POST请求
	//public static void main(String[] args) throws Exception{
	//发送GET请求
	//    String s = HttpRequest.sendGet("http://127.0.0.1:8080/index",null);
	//    System.out.println(s);
	//发送POST请求
	//    String s1 = HttpRequest.sendPost("http://localhost:8080/addComment", "questionId=1&content=美丽人生");
	//    System.out.println(s1);
	//}
}
